1. Technical Field
The present invention relates to indoor tire testing equipment and in particular to a shroud placed about the tire for collection of a dispensed powder and particles released from the tire during contact with the abrasive surface of a road wheel to prevent dispersion of the powder and particles into the surrounding atmosphere. Even more particularly, the invention relates to such a collection shroud which provides a controlled environment for the area of contact between the abrasive surface of the road wheel and the tire tread.
2. Background Information
Various types of indoor tire wear testing apparatus have been developed in order to test a tire in an environment closely simulating actual outdoor driving conditions. In these wear test apparatus, a tire is mounted on a test machine and loaded against a rotating road wheel or drum which has an abrasive surface attempting to simulate the actual road surface. This type of testing is typically performed in a temperature controlled test cell or room in order to attempt simulating actual outdoor driving conditions. As the tire is tested, tread rubber is slowly worn away from the tread. To prevent the abraded gummy rubber particles from adhering to the tire and/or the abrasive surface of the road wheel, various types of fine powder are generally sprayed or dusted onto the abrasive surface of the road wheel which mates with the rubber particles to prevent gumming. This is essential in order to achieve more realistic tire wear. Furthermore, it is essential that the powder and rubber particles be collected and removed to a remote location to prevent its accumulation in the test area. Some examples of prior art tire testing machine and dust collection systems are shown in U.S. Pat. Nos. 2,766,618; 3,899,917; 4,272,301; 4,938,055; 5,504,968 and 5,703,284.
Although these prior tire test machines and dust collection systems perform satisfactory for their intended use, it is desirable that, in addition to providing an efficient dust and particle collection system, to be able to control the environment such as the temperature, moisture, etc. adjacent the contact area between the road wheel and tire tread, to more closely simulate actual outdoor driving conditions affecting tire wear.
The present invention provides a collection shroud for an indoor tire test machine which efficiently collects powder and particles released from the tire during testing and transports it to a remote location to prevent the powder and particles from being discharged into the surrounding atmosphere.
The shroud of the present invention comprises a movably mounted housing which facilitates placement and removal of a tire on and from the tire test machine, which shroud partially encloses the tire in a chamber located adjacent a pair of vacuum collection units in order to retain the powder and particles in the housing for subsequent removal by the vacuum units.
The collection shroud furthermore permits control of ambient temperature, moisture, etc. in the immediate area around the tire when enclosed by the shroud as opposed to controlling the ambient temperature of the entire test room.
Another feature of the invention is that the collection shroud permits a range of tire sizes to be tested and permits the easy access for installation and removal of the tire before and after testing.
A further feature of the invention is providing a freestanding floor mounted shroud in which the collected powder and particles are channeled through ducts into commercially available dust collection systems before it becomes airborne within the test room, which allows tire wear testing to be performed in either direction of rotation without affecting the operation of the vacuum and ambient control systems, and which provides a seal between the shroud and tire test equipment.
Another aspect of the invention is forming the collection shroud of sheet metal panels which enclose the tire on four sides with the fifth side being partially open to permit dynamic movement of the test machine for loading the tire against the road wheel, and which uses brush assemblies to minimize leakage of powder and particles from the partially open side during testing of a tire and dispensing of the powder thereon.